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96 lines
4.0 KiB
96 lines
4.0 KiB
/* Copyright (c) 2015, The Linux Foundation. All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions are |
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* met: |
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* * Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* * Redistributions in binary form must reproduce the above |
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* copyright notice, this list of conditions and the following |
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* disclaimer in the documentation and/or other materials provided |
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* with the distribution. |
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* * Neither the name of The Linux Foundation, nor the names of its |
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* contributors may be used to endorse or promote products derived |
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* from this software without specific prior written permission. |
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* |
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* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED |
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT |
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS |
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR |
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* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE |
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* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN |
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* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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* |
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*/ |
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#ifndef __LOC_HEAP__ |
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#define __LOC_HEAP__ |
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#include <stddef.h> |
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#include <string.h> |
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// abstract class to be implemented by client to provide a rankable class |
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class LocRankable { |
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public: |
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virtual inline ~LocRankable() {} |
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// method to rank objects of such type for sorting purposes. |
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// The pointer of the input node would be stored in the heap. |
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// >0 if ranks higher than the input; |
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// ==0 if equally ranks with the input; |
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// <0 if ranks lower than the input |
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virtual int ranks(LocRankable& rankable) = 0; |
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// convenient method to rank objects of such type for sorting purposes. |
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inline bool outRanks(LocRankable& rankable) { return ranks(rankable) > 0; } |
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}; |
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// opaque class to provide service implementation. |
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class LocHeapNode; |
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// a heap whose left and right children are not sorted. It is sorted only vertically, |
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// i.e. parent always ranks higher than children, if they exist. Ranking algorithm is |
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// implemented in Rankable. The reason that there is no sort between children is to |
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// help beter balance the tree with lower cost. When a node is pushed to the tree, |
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// it is guaranteed that the subtree that is smaller gets to have the new node. |
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class LocHeap { |
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protected: |
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LocHeapNode* mTree; |
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public: |
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inline LocHeap() : mTree(NULL) {} |
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~LocHeap(); |
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// push keeps the tree sorted by rank, it also tries to balance the |
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// tree by adding the new node to the smaller of the subtrees. |
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// node is reference to an obj that is managed by client, that client |
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// creates and destroyes. The destroy should happen after the |
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// node is popped out from the heap. |
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void push(LocRankable& node); |
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// Peeks the node data on tree top, which has currently the highest ranking |
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// There is no change the tree structure with this operation |
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// Returns NULL if the tree is empty, otherwise pointer to the node data of |
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// the tree top. |
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LocRankable* peek(); |
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// pop keeps the tree sorted by rank, but it does not try to balance |
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// the tree. |
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// Return - pointer to the node popped out, or NULL if heap is already empty |
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LocRankable* pop(); |
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// navigating through the tree and find the node that ranks the same |
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// as the input data, then remove it from the tree. Rank is implemented |
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// by rankable obj. |
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// returns the pointer to the node removed; or NULL (if failed). |
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LocRankable* remove(LocRankable& rankable); |
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#ifdef __LOC_UNIT_TEST__ |
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bool checkTree(); |
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uint32_t getTreeSize(); |
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#endif |
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}; |
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#endif //__LOC_HEAP__
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